The Zempoala Ruins are in a town called Zempoala. Clever how they did that. The pueblo is built on the ruins. There are ruins all over town. Some are behind fences, some are not. They date to the late Olmec period, maybe about 1500 years before the Spanish arrived. It was a city of 20-30,000 people. The ruins are totally restored in this area shown and they allow you to go up on a couple of them.